EP2770597A1 - Method for testing a plurality of spatially distributed protection devices of an energy supply network and corresponding testing system - Google Patents

Abstract

The method involves creating (S1) an initial test sequence, and outputting (S2) the test sequence at the protection units, where the expenses of the protection units are detected (S3) to expand the protection units due to the test sequence. The expenditure and the generation of inputs for the protection units are analyzed (S4) depending on the expenses, if the inputs are not the part of the test sequence. Independent claims are included for the following: (1) a profile system with a control unit for testing multiple spatially distributed protection units of an energy supply network; and (2) a computer program product for executing a testing method.

Description

The present invention relates to a method and a test system for testing or testing a plurality of spatially distributed protective devices which are used to protect a power supply network (eg a high-voltage network).

Power grid protection devices include one or more protection devices that monitor and analyze for process variables (eg, power, voltage, but also switching states of, for example, power switches or conditions of, for example, transformers) of the power grid. If, by this analysis, the protection device detects an error in its assigned protection area of the power supply network, the protection device issues switching commands, in particular to control a circuit breaker with which the detected fault is isolated by disconnecting the corresponding part of the power supply network. For this purpose, the circuit breaker interrupts the energy flow of the power grid by the circuit breaker, e.g. breaks a line of the power grid or the power flow on one side of a transformer. Some protective devices or protective devices are also able to output switching commands after a certain pause time to close the previously opened circuit breaker again. If the fault no longer exists when the circuit breaker is closed, the protective device or the protective device returns to the normal monitoring of the power supply network. If, on the other hand, the fault still exists when the circuit-breaker is closed, this detects the protective device or the protective device so that the circuit-breaker is opened again immediately by means of the protective device or the protective device.

An energy supply network is understood to mean in particular a network which comprises lines which have voltages of more than 10 kV with one another. The energy supply network referred to here comprises on the one hand energy transmission networks with voltages of over 100 kV and on the other so-called energy distribution networks with voltages of more than 10 kV (eg of 20 kV). This can be an alternating voltage (eg 50 Hz) or a DC voltage. A power switch is configured to interrupt an active electrical connection of such a high voltage line. Therefore, a circuit breaker can switch high overload currents and short-circuit currents (up to 800 kA) and must be able to hold them for a specified period of time and then switch them off again.

The testing of these protective devices is done according to the prior art usually by testing the individual protection device in an isolated test. Proof of the correct system behavior, i. The correct interaction of all components (in particular protective devices) is done according to the prior art usually not by a functional test, but by a revision of the relevant technical documentation.

Therefore, the present invention has the object to improve the testing of spatially distributed protection devices of a power supply network, so that the correct interaction of the spatially distributed protection devices is checked with test sequences generated for this purpose.

According to the invention, this object is achieved by a method for testing a plurality of spatially distributed protective devices of a power supply network according to claim 1, by a test system for testing a plurality of spatially distributed protection devices of a power supply network according to claim 10, by a control device according to claim 12 and by a computer program product according to claim 13 solved. The dependent claims define preferred and advantageous embodiments of the present invention.

1. a) Erstellen einer initialen Prüfsequenz, mit welcher eine oder mehrere Schutzeinrichtungen getestet bzw. geprüft werden können. Dabei umfasst jede Prüfsequenz sowohl Eingaben für die zu prüfende Schutzeinrichtung in Form von Prozessgrößen des Energieversorgungsnetzes und kann auch Soll-Ausgaben (Prüfantworten), welche von der jeweils geprüften Schutzeinrichtung abhängig von den Eingaben ausgegeben werden sollen, umfassen.
2. b) Ausgeben bzw. Anlegen der Prüfsequenz an die Schutzeinrichtungen.
3. c) Erfassen der Ausgaben der geprüften Schutzeinrichtungen, wobei die jeweilige Schutzeinrichtung diese Ausgaben aufgrund der an die jeweilige Schutzeinrichtung angelegte Prüfsequenz ausgibt.
4. d) Analysieren der Ausgaben und Erzeugen von Eingaben für die Schutzeinrichtungen abhängig von den Ausgaben. Wenn die Ausgaben einer Schutzeinrichtung (beispielsweise ein Schaltbefehl zum Öffnen eines Leistungsschalters) zu Änderungen der Prozessgrößen anderer Schutzeinrichtungen führen, werden entsprechend dieser Ausgaben Eingaben (in Form der geänderten Prozessgrößen) für diese anderen Schutzeinrichtungen erzeugt.
   Wenn diese (neu) erzeugten Eingaben noch nicht Bestandteil der Prüfsequenz sind, wird die Prüfsequenz um die entsprechenden (neu) erzeugten Eingaben erweitert, und das Verfahren kehrt zu dem Schritt b zurück bzw. fährt mit dem Schritt b fort.
   Wenn dagegen die (neu) erzeugten Eingaben bereits Bestandteil der Prüfsequenz sind, fährt das Verfahren beim folgenden Schritt e fort.
5. e) Auswerten der Ausgaben der Schutzeinrichtungen. Spätestens in diesem Schritt wird überprüft, ob die im Rahmen der Prüfung von den Schutzeinrichtungen erzeugten Ausgaben den Soll-Ausgaben entsprechen, welche beispielsweise Bestandteil der Prüfsequenz sein können. Dabei legt eine Soll-Ausgaben insbesondere fest, was (beispielsweise in Form von Binärdaten) die jeweilige Schutzeinrichtung auszugeben hat und wann die jeweilige Schutzeinrichtung die Soll-Ausgabe auszugeben hat (z. B. nach einem ersten Zeitintervall und vor Beendigung eines zweiten Zeitintervalls, welche beide mit dem Anlegen der Prüfsequenz beginnen). Das Ergebnis der Auswertung aller Ausgaben der Schutzeinrichtungen ist, ob die Schutzeinrichtungen die Prüfsequenz korrekt abgearbeitet haben oder nicht.

In the context of the present invention, a method is provided for testing a plurality of spatially distributed protective devices of a power supply network. Each of these protective devices is designed to be at the Detecting a fault in an area monitored by the respective protective device area of the power grid to isolate this error (in particular by opening an associated circuit breaker). The method according to the invention comprises the following steps:

1. a) Creating an initial test sequence with which one or more protective devices can be tested or tested. In this case, each test sequence comprises both inputs for the protective device to be tested in the form of process variables of the energy supply network and may also include target outputs (test responses) which are to be output by the respective tested protective device depending on the inputs.
2. b) outputting or applying the test sequence to the protective devices.
3. c) recording the expenses of the tested protective devices, whereby the respective protective device outputs these outputs on the basis of the test sequence applied to the respective protective device.
4. d) Analyze the outputs and generate inputs for the protection devices depending on the outputs. If the outputs of a protection device (for example, a circuit breaker opening switch command) result in changes in the process variables of other protection devices, inputs (in terms of changed process variables) are generated for these other protection devices according to these outputs.
   If these (newly) generated inputs are not yet part of the test sequence, the test sequence is extended by the corresponding (newly) generated inputs, and the method returns to step b or proceeds to step b.
   If, on the other hand, the (newly) generated inputs are already part of the test sequence, the method continues at the following step e.
5. e) Evaluating the expenses of the protective devices. At the latest in this step, it will be checked whether the expenses generated by the guards during the test correspond to the target expenditure, which may be part of the test sequence, for example. Specifically, a target output specifies what the respective protection device has to output (for example in the form of binary data) and when the respective protection device has to output the target output (eg after a first time interval and before the end of a second time interval) both begin with the creation of the test sequence). The result of the evaluation of all outputs of the protective devices is whether the protective devices have correctly executed the test sequence or not.

The steps b) and c) are carried out in particular time-synchronized, so that the test sequence is applied by all test devices time synchronously to the protective devices and simultaneous outputs receive the same time stamp. This is achieved by high accuracy clocks in the test equipment, e.g. be synchronized by GPS. As a result, the times at which certain outputs of the protective devices are detected can also be taken into account in the analysis in step d) or in the evaluation in step e).

In contrast to the prior art, the interaction of different protective devices is advantageously also checked, even if these protective devices are spatially separated. Spatially distributed protective devices mean that at least two of these protective devices are at least 1 km apart. But it is also possible that at least two of these protection devices several tens of kilometers, several 100 km or even several 1000 km apart.

The outputs of the respective protective device can include both a switch opening command, with which a circuit breaker is opened, and a restart command, with which the circuit breaker is closed again.

If the inputs to the protection devices are currents or voltages, these can be determined by specifying fixed amplitudes, Phase angles and / or frequencies are defined. In addition, however, these inputs may also be defined in the form of a ramp by, for example, increasing or decreasing the amplitude of a voltage or current from a first value to a second value within a certain period of time.

By taking into account both the opening and the re-closing of circuit breakers when testing the protective devices, the system which in addition to the spatially distributed protective devices to be tested comprises the power supply network is advantageously tested in its interaction. Since the observed switching commands (for the circuit breakers) are reflected in the process variables, the opening and re-closing of the circuit breakers is advantageously simulated in the inventive testing of the protective devices.

The generation of new inputs depending on the detected outputs (e.g., switching commands) of the protective devices is carried out in particular by means of a model of the power supply network protected by the protective devices. On the basis of the recorded outputs, this model is used to determine changes in the process variables of the energy supply network, from which the inputs for the protective devices to be tested are derived.

By using the model of the energy supply network, the temporal behavior of process variables of the energy supply network at a first location (ie for a first protection device) can advantageously be determined or simulated if a circuit breaker is closed at a second location (for example by a switching command of a second protection device) becomes. In other words, the model of the power supply network can simulate the effects of outputs (eg, switching commands) of the second protection device on the process variables detected by the first protection device, even if the two protection devices are many kilometers apart.

According to the invention, this model can be a static, a dynamic or a transient model.

In doing so, the static model models the steady state of the power grid, while the dynamic model additionally models switching operations of e.g. Power circuit breakers can model. The transient model is the most accurate of the three models because the transient model models the process variables of the power grid even during switching operations with an exact time behavior.

The protective device protects the power supply network or more precisely the area of the power supply network assigned to the protective device, in which the protective device outputs a switching command upon detection of a fault in the power supply network. The switching command is transmitted to a circuit breaker associated with the protection device, which interrupts a high voltage line or part of the power supply network upon receipt of this switching command to thereby protect the protected area of the power supply network from the effects of the fault.

For monitoring the power supply network, the protective device detects process variables of the power supply network, such as, for example, a current flowing in a high-voltage line or a high voltage prevailing between two high-voltage lines. For this purpose, the voltage or the current is advantageously converted by means of a converter connected to the energy supply network of the respective protective device, so that the protective device measures the process variables in the form of a comparatively low voltage (eg 100 V) and / or in the form of a comparatively low current (eg 1 A). In addition, there are alternative transducers (eg Rogowski converters) which convert the high voltage and / or the high current directly into small signals (mV range) or digital signals, which are then monitored by the connected protective device. Depending on the process variables converted in this way, the protective device determines whether there is a fault in the energy supply network. It lies the For example, an error occurs when the current rises above a current threshold or when the voltage drops below a voltage threshold.

In this case, the test sequence of the protective device to be tested can be supplied in the form of small signals, digital signals (for example via a network connection (for example LAN)) (according to IEC 61850-9-2). But it is also possible that the test sequence in the form of classical analog signals (volts range) is specified.

In addition, it is possible for one of the protection devices to be in a communication connection via a communication channel with a low latency (for example via an optical waveguide carried along on the high-voltage line) to another of the protection devices. As a result, these two protective devices can acquire information (eg process variables, error states or (upcoming) switching commands) from the respective other protective device in almost real time. Depending on this information, the respective protective device can decide whether or not the fault is isolated from the respective protective device when a fault occurs in the power supply network.

If, for example, a protective device detects an error on the basis of the process variables it detects and at the same time learns from the information transmitted via the communication channel that this error has also been detected by another protective device, the protective device can, for example, delay the opening of the circuit breaker associated with it to wait and see if the fault can be isolated from the other protection device.

The present invention may also include a test in which the above-described communication channel between the protection devices is intentionally interrupted to check the so-called backup behavior (ie the protection behavior without communication channel) of the protection devices.

Advantageously, the method according to the invention is carried out automatically by a central control device, which communicates with each protective device to be tested, for example via test devices.

By the locally distributed testing devices are each in communication with the central control device, on the one hand advantageously each test device can be controlled and controlled by the control device. On the other hand, the test results of all protective devices, which are detected by the respective test device, are available centrally in the control device.

• ● Eine Eingabe in Form von Prozessgrößen (z. B. Strom, Spannung) des Energieversorgungsnetzes für eine Schutzeinrichtung.
• ● Ein Zustand (z.B. Schaltzustand) eines Leistungsschalters, ein Zustand (z.B. Schaltzustand) eines Trenners oder eine andere an einen Binäreingang der Schutzeinrichtung angeschlossene binäre Prozessgröße.
• ● Informationen oder Daten, welche von einer Schutzeinrichtung über einen Kommunikationskanal an eine andere Schutzeinrichtung gesendet werden.

According to another embodiment of the invention, a sequence of output steps may be specified. Each of these output steps defines or comprises one or more inputs or test variables. An input or test variable is understood to mean at least one element from the following group:

• ● An input in the form of process variables (eg current, voltage) of the power supply network for a protective device.
• ● A state (eg switching state) of a circuit breaker, a state (eg switching state) of a disconnector or another binary process variable connected to a binary input of the protective device.
• ● Information or data sent from one protection device to another protection device via a communication channel.

• ● Ein Ereignis, welches bei Ablauf einer vordefinierten Zeitspanne eintritt.
• ● Ein Ereignis, welches beim Eintreffen eines bestimmten Datums, welches von einer Schutzeinrichtung über einen Kommunikationskanal an eine andere Schutzeinrichtung gesendet wird, eintritt.
• ● Ein Ereignis, welches eintritt, wenn sich ein bestimmter Leistungsschalter öffnet.
• ● Ein Ereignis, welches eintritt, wenn sich ein bestimmter Leistungsschalter schließt.
• ● Ein sonstiges Ereignis, welches (z.B. bei einer vordefinierten Änderung einer Prozessgröße) eintritt und von der Prüfeinrichtung durch die Auswertung der binären Eingänge detektiert werden kann.

The output steps are output to the protection devices as the test sequence. In this case, an order in which the output steps are output to the protective devices, determined by so-called trigger events. In other words, the order in which trigger events occur indicates the order in which the output steps are output to the protection devices as a test sequence. In this case, each of the trigger events can be formed from an event group depending on at least one event, the event group comprising the following events:

• ● An event that occurs at the end of a predefined period of time.
• ● An event that occurs when a specific date, which is sent by a protection device via a communication channel to another protection device, occurs.
• ● An event that occurs when a particular circuit breaker opens.
• ● An event that occurs when a particular circuit breaker closes.
• ● Another event that occurs (eg with a predefined change of a process variable) and that can be detected by the test device by evaluating the binary inputs.

In this case, the occurrence of a specific trigger event can lead to the immediate abort of the current output step or to a delayed abort of the current output step. After the termination of the current output step, an output step dependent on the respective trigger event is activated. In this case, it is also possible for the output steps to have a predefined sequence and, after the abort of the current output step, to activate the output step following this order if no other output step is defined by the triggering trigger event. The output step following the current output step may depend on only the current output step (in this case, a trigger event determines the time of transition from the current to the following output step), only the present trigger event, or both the current output step and the present trigger event be.

In other words, upon the occurrence of a particular trigger event, the test values or inputs applied to the protection devices according to the current output step are immediately or delayed replaced by the test values or inputs defined by the next output step, which depends on the present trigger event aborted output step follows.

A trigger event may be present if exactly one event from the above-mentioned event group is present. For example, one trigger event may occur when one circuit breaker is closed while another trigger event may occur when the same circuit breaker is opened. However, it is also possible that a specific trigger event is defined by the logical combination of multiple events. For example, one trigger event may occur when two (or more) power switches each close (logical AND), while another trigger event may be present when at least one of two (or more) circuit breakers closes (logical OR).

In particular, according to the further embodiment, the inputs to the protection devices are not only made dependent on the outputs of the protection devices, but the inputs may change even after a predetermined period of time has passed (regardless of the outputs).

In the further embodiment described here, the inputs for the protective devices are generated depending on the outputs of the protective devices based on the predetermined output steps, while the inputs in the embodiments described above are determined, for example, based on a model of the power grid depending on the outputs. Thus, in this further embodiment, in contrast to the creation of inputs based on a network simulation (i.e., on the model of the power grid), a state change is also possible which would not occur in reality. This advantageously opens up additional possibilities in which relatively simple fault scenarios can be tested, which in reality are very difficult (if at all) to generate.

Also in this embodiment, the response of a single or multiple protection devices affects the creation of the final verification sequence. In addition, possible latencies on the communication link between the testers prevent conventional creation of the final test sequence without recursion. In other words, the present Invention also required for the preparation of the final test sequence and thus for testing a plurality of spatially distributed protection devices when the inputs for the protective devices using the given output steps depending on the outputs of the protective devices are obtained (as the further embodiment describes).

In particular, the initial test sequence according to the further embodiment is output to the protection devices without events or triggering events (i.e., without switching reactions of circuit breakers). Subsequently, the reactions of the protective devices to the (initial) test sequence are evaluated and the corresponding trigger events are calculated, with which further inputs for the protective devices are created, whereby the test sequence is extended. This extended test sequence is output again to the protective devices, which can then lead to further trigger events. This loop is repeated until no further relevant outputs of the protective devices are detected, which would lead to a further adaptation of the test sequence.

In the context of the present invention, a test system is also provided with which a plurality of protective devices of a power supply network arranged at spatially distributed locations (for example substations) are tested or tested. The test system comprises a control device and a plurality of test devices. At each location of the protective devices, at least one of the test equipment is present. The control device has a communication connection to each of these test devices. The respective test device is designed to test one or more protective devices which are present at the same location as the respective test device. In addition, the test system is designed for carrying out the method according to the invention.

The advantages of the test system according to the invention correspond to the advantages of the method according to the invention, which have been carried out in advance in detail, so that a repetition is dispensed with here.

The control device can be integrated with one of the test devices, so that the control device and the corresponding test device are integrated in the same device.

In addition, a control device for a test system for testing a plurality of spatially distributed protective devices of a power supply network is provided. In this case, the control device is designed to communicate with a plurality of test devices via corresponding communication links (e.g., Internet, telephone network) each associated with one or more protection devices. Each of these testing devices is designed to test one or more protective devices. The control device itself is designed to carry out the method according to the invention.

The communication connection with which the test devices communicate with the control device can also be a slow connection with a high latency (for example, a mobile radio network, UMTS), since the present invention advantageously does not provide real-time requirements with respect to this communication connection.

Furthermore, the present invention describes a computer program product, in particular a computer program or software, which can be loaded into a memory of a programmable controller or a computer. With this computer program product, all or various previously described embodiments of the method according to the invention can be carried out when the computer program product is running in the controller or in the computer. The computer program product may require program resources, eg libraries and auxiliary functions, in order to implement the corresponding embodiments of the methods. In other words, with the claim directed to the computer program product, in particular a computer program or a software is to be protected, with which one of the above-described embodiments of the method according to the invention can be carried out or which executes this embodiment. This may involve the software a source code (eg C ++) that still needs to be compiled (translated) and bound or that needs to be interpreted only, or is an executable software code that can only be loaded into the corresponding computation unit (computer) for execution.

In the following, the present invention will be shown again from a different angle.

The present invention tests or tests a plurality of spatially distributed protective devices of a power supply network. In this case, in particular by a corresponding model of the energy supply network, process variables are calculated at the installation locations of the protective devices to be tested, and the protective devices are predefined for testing with the aid of the testing devices. Thus, the normal operation, fault conditions and shutdown conditions are modeled or simulated, so that the protective devices are tested for different operating modes and states of the system (energy supply network including protective devices). The model used to calculate the process variables has an influence on the exact values of the process variables as well as on the course of the process variables, as they occur, for example, when an error occurs or when the circuit breakers are switched.

For this, the following problem must be solved. The delay times which occur in a transmission of a switching operation for a circuit breaker via the communication network (eg Internet, telephone network), via which the testing devices are connected to the control device, far exceed the propagation speed of the effects of switching over the power supply network. The present invention solves this problem by gradually building or expanding the test sequence. It is based on the premise that the respective protective device behaves deterministically, so that the respective protective device (including the associated circuit breaker) during repeated application of the same test parameters within certain tolerances an identical behavior (for example, when issuing switching commands) shows.

In order to carry out the present invention, the test devices in particular supply analog current / voltage inputs of the protective devices with corresponding test parameters or inputs. For checking, it may also be helpful if certain binary inputs of the protective devices, with which, for example, switch positions of circuit breakers are signaled, are supplied with corresponding test parameters or inputs.

• ● Die Ergebnisse der Tests aller Schutzeinrichtungen sind insbesondere auf der zentralen Steuereinrichtung verfügbar und können daher zentral ausgewertet werden.
• ● Da auch die Reaktion des Energieversorgungsnetzes auf Schaltbefehle bei der Prüfung der Schutzeinrichtungen berücksichtigt wird, erfolgt insbesondere eine Rückkopplung zwischen dem zu prüfenden System (Energieversorgungsnetz mit Schutzeinrichtungen) und dem für die Prüfung verwendeten Modell des Systems.
• ● Bei der Prüfung können alle Ausgaben der Schutzeinrichtungen insbesondere auch Wiedereinschaltbefehle für Leistungsschalter) berücksichtigt werden.
• ● Die erfindungsgemäße Prüfung prüft auch ein korrektes Verhalten des Systems hinsichtlich von Zyklen von Öffnen und Wieder-Schließen von Leistungsschaltern, so dass durch falsche Einstellungen der verschiedenen Schutzeinrichtungen auftretende Diskrepanzen und ein nichtsynchrones Systemverhalten bei der Prüfung berücksichtigt wird und gegebenenfalls zu einem negativen Ergebnis der Prüfung führt.

Compared with the prior art, the present invention offers the following advantages:

• ● The results of the tests of all protective devices are available in particular on the central control device and can therefore be evaluated centrally.
• ● As the response of the power grid to switching commands is also taken into account when testing the protective devices, in particular there will be feedback between the system under test (power system with protection devices) and the model of the system used for the test.
• ● During the test, all outputs of the protective devices, in particular also reclosing commands for circuit breakers, can be taken into account.
• ● The test according to the invention also checks for correct behavior of the system with regard to cycles of opening and re-closing of circuit breakers so that discrepancies and non-synchronous system behavior resulting from incorrect settings of the various protective devices are taken into account during the test and, if appropriate, a negative result of the test leads.

The present invention is suitable for carrying out tests of protective devices with which a power supply network is protected. Of course, the present invention is not limited to this preferred application because the present invention can also be used to test protective devices that have just been manufactured or serviced.

The present invention will be explained in more detail below with reference to the accompanying drawings with reference to preferred embodiments according to the invention.

In Fig. 1 is a test system according to the invention together with a power supply network, which is protected by two protective devices shown.

Fig. 2 shows a flowchart of a method according to the invention.

In Fig. 1 a power grid in the form of a single overhead line 3 is shown. According to the invention, a power supply network can comprise a plurality of overhead lines, other high-voltage lines, parallel lines and transformers, which are connected in a network-like manner. The overhead line 3 terminates at both ends in each case on a busbar SS ₁ , SS ₂ in different substations UW ₁ , UW ₂ . Within the respective substation is in each case a circuit breaker, with which the electrical connection between the two substations UW ₁ , UW ₂ connecting part of the overhead line 3 and the respective busbar SS ₁ , SS ₂ can be interrupted. In addition, located within each substation UW ₁ , UW ₂ each have a converter, with which a guided by the overhead line 3 heavy current (phase current) and a voltage applied to the overhead line 3 high voltage is converted, the result of this conversion in the form of a current and a voltage of lower amplitude (eg 1 A and 100 V) are supplied as process variables of the respective protective device. Based on these process variables, the respective protective device monitors the power supply network or the overhead line 3. The point at which the respective circuit breaker and the respective converter are located is in Fig. 1 denoted by K ₁ or K ₂ .

When an error 5 (for example, a short circuit) of the overhead line 3 occurs, the respective protective device SE ₁ ; SE ₂ this error 5 based on the process variables, for example, the current over a current threshold increases or the voltage falls below a voltage threshold. As soon as the respective protective device SE ₁ ; SE ₂ detects the error 5, it issues a switching command to its associated circuit breaker to interrupt the electrical connection and thus isolate the error 5. After a predetermined pause time after detecting the error 5, the respective protective device SE ₁ ; SE ₂ issue a switching command to its associated circuit breaker to restore the electrical connection. If the error 5 still exists at this time, this detects the respective protection device SE ₁ ; SE ₂ based on the supplied process variables of the overhead line 3 and is another switching command to interrupt the electrical connection with its associated circuit breaker again.

In addition, the two protective devices are connected via a communication channel 2 communication technology. The two protective devices SE ₁ , SE ₂ can transmit specific information (eg process variables, switching commands) in near real time via this communication channel 2.

For testing the protective devices SE ₁ , SE ₂ exists in each substation UW ₁ , UW ₂ a test device PE ₁ , PE ₂ , wherein the respective test device PE ₁ , PE ₂ by means of a test line PL ₁ , PL ₂ with the same in the substation UW. ₁ , UW ₂ arranged protective device SE ₁ ; SE _{2 is} connected. In addition, there is a central controller 1, which is connected via a communication line 6 and a WAN communication link 4 with two testing devices PE ₁ , PE ₂ .

The test devices PE ₁ , PE ₂ are each equipped with a very accurate clock, the clocks of the test facilities PE ₁ , PE _{2 are} usually synchronized by GPS to have exactly the same time. Time-synchronous clocks are of great importance when creating the test sequence and when detecting the outputs of the individual protective devices SE ₁ , SE ₂ .

To test the protective devices SE ₁ , SE ₂ , the protective devices SE ₁ , SE _{2 are separated} from the power supply network 3 by the control lines SL ₁ , SL _{2 are} interrupted. During the test, the protective equipment SE ₁ ; SE _2, the process variables normally acquired by the converter via the respective test line PL ₁ ; PL ₂ and give the output in normal operation via the control line SL ₁ , SL ₂ switching commands via this test line PL ₁ ; PL ₂ off. The power supply network is therefore not protected during the test of the protective devices SE ₁ , SE ₂ , but also not disrupted by the test switching commands disturbed.

In Fig. 2 a flow chart of a method according to the invention for testing a plurality of spatially distributed protective devices SE ₁ , SE _{2 of} a power supply network is shown.

In step S1, a test sequence for one, several or all of the protective devices SE ₁ , SE ₂ to be tested is created. This test sequence is used to check whether the respective protective device SE ₁ ; SE ₂ during the transition from normal operation to an error state (ie the respective protection device SE ₁ , SE ₂ detects a fault in the power supply network) behaves correctly. For this purpose, the respective protective devices SE ₁ , SE ₂ via the test line PL ₁ ; Supplied PL ₂ process variables, which would be detected in case of failure from the power grid or from the overhead line 3.

In step S2, the test sequence is distributed by the control device 1 to the test devices PE ₁ , PE ₂ and output from these test devices PE ₁ , PE ₂ at exactly the same time to the respective protective devices SE ₁ , SE ₂ by corresponding test patterns of the respective safety device SE ₁ ; SE ₂ via the respective test line PL ₁ ; PL _{2 are} supplied. The response of the protective devices SE ₁ , SE ₂ to these test patterns is detected in step S3 by the outputs of the respective protective device SE ₁ ; SE ₂ of the respective test device PE ₁ , PE ₂ on the respective test line PL ₁ ; PL ₂ and provided with a very accurate time stamp. These outputs include, for example, switching commands to the respective protection device SE ₁ ; SE ₂ associated circuit breaker.

In step S4, the outputs detected in the previous step S3 (particularly Switching commands). In this analysis, it is checked whether an output of a protective device SE ₁ , SE _{2 changes} the process variables of the power supply network 3, which is the case, for example, when the outputs comprise a switching command for opening a currently closed circuit breaker. With the aid of a model of the energy supply network 3, in this case, starting from the switching commands detected in step S3, the process variables at all those points K ₁ , K _{2 of} the energy supply network 3 are simulated, at which the process variables of the protective devices SE ₁ , SE ₂ in normal operation ( Non-test operation). From the process variables simulated in this way, corresponding inputs for the protective devices SE ₁ , SE _{2 result} . (For example, a switching command of the protective device SE _{1 leads} to opening of the circuit breaker at K ₁ and thus to a change of the process variables at the point K ₂ , which in turn leads to a change in the inputs of the protective device SE ₂ fed via the test line PL _2. )

If step S5 is run through at least a second time, it is checked in step S5 whether the current outputs within certain tolerances (deterministic) with the outputs of the previous run match. A negative result of step S5 does not necessarily lead to a negative test result. In the normal case, the method is repeated in the case of a negative result of step S5, with the tolerances being increased if necessary. The evaluation of the result of step S5 can also be done manually. In this case, the procedure will be repeated after a negative result only if the technician supervising the test agrees.

In step S6, it is checked whether the inputs generated in the previous step S4 are already included in the test sequence. In the first pass of step S6, this will generally not be the case, provided switching commands have been detected in step S3. If inputs exist which are not yet included in the test sequence, these inputs are included in the test sequence in step S7. Subsequently, the method according to the invention continues again at step S2. It is therefore a recursive procedure.

With a renewed passage of steps S2 to S6, the transition from normal operation to the error state and from there to the state after switching operations of the circuit breakers initiated by the protective devices SE ₁ , SE _{2 are} checked with the test sequence modified in the last step S7. In this case, it is again checked in step S6 whether in the previous step S4 there are outputs (in particular switching commands) which did not exist in the previous pass. This is the case, for example, when one of the protective devices SE ₁ , SE ₂ issues a switching command for re-closing the circuit-breaker assigned to it.

The method proceeds through steps S2 to S6 until the protective devices SE ₁ , SE ₂ output no further or new outputs (in particular switching commands). If so, the process branches to step S8 in which the outputs of the protectors SE ₁ , SE ₂ detected by the respective testers are evaluated to produce a test result.

In general, the inclusion of further inputs in the test sequence also includes the inclusion of target outputs, which are issued by the protection devices SE ₁ , SE ₂ due to the newly recorded inputs. For this reason too, it is possible for example in step S4 to check in each case during the analysis of the outputs, whether the respective outputs of the protective devices SE ₁ , SE ₂ detected by the test devices PE ₁ , PE ₂ are correct or whether there has already been a malfunction of the Safety devices SE ₁ , SE _{2 was} detected, which could lead to a negative test result and thus to premature termination of the test.

In addition, it can be verified at each further pass of steps S2 to S6, whether the outputs of the protective devices SE ₁ , SE ₂ the outputs of the protective device SE ₁ ; SE ₂ in the respective previous pass correspond, so in particular in each case the same switching commands have been issued. If this is not the case, the exam can also be done with a negative result will be terminated.

LIST OF REFERENCE NUMBERS

1

control

2

communication channel

3

overhead line

4

WAN communication link

5

error

6

communication line

K ₁ , K ₂

Node (circuit breaker and converter)

PE ₁ , PE ₂

test equipment

PL ₁ , PL ₂

Test lead

SL ₁ , SL ₂

control line

S1-S8

step

SS ₁ , SS ₂

bus

USW ₁ , USW ₂

substation

Claims (13)

Method for testing a plurality of spatially distributed protective devices (SE ₁ , SE ₂ ) of a power supply network (3),
each of the protective devices (SE ₁ , SE ₂ ) being designed to isolate the fault (5) in the power supply network (3) in the event of a fault (5) in the power supply network (3),
the method comprising the steps of: a: creation of an initial test sequence, b: outputting the test sequence to the protective devices (SE1, SE2), c: detecting outputs of the protective devices (SE1, SE2) which output the protective devices (SE1, SE2) on the basis of the test sequence, d: analyzing the outputs and generating inputs for the protection devices (SE1, SE2) depending on the outputs, wherein if the inputs are not part of the test sequence, these inputs are included in the test sequence and continued with step b, while otherwise using Step e continues, and e: evaluation of all outputs of the protective devices (SE1, SE2), wherein each test sequence comprises inputs in the form of process variables of the energy supply network (3) for at least one of the protective devices (SE ₁ , SE ₂ ). Method according to claim 1,
characterized,
in that the outputs of the at least one of the protective devices (SE ₁ , SE ₂ ) are a switch opening command, with which a circuit breaker for isolating the fault (5) is opened, and / or a reclosing command, with which an error (5) can be isolated by closing a circuit breaker Circuit breaker is reversed include. Method according to claim 1 or 2,
characterized,
that the generation of the inputs depends on the outputs by Based on the outputs of a model of the power grid (3) changes in the process variables of the power grid (3) can be determined. Method according to claim 3,
characterized,
that the model is a static, a dynamic or a transient model. Method according to one of the preceding claims,
characterized,
in that , when an error (5) occurs in the power supply network (3), each protection device (SE ₁ , SE ₂ ) issues a circuit breaker opening command to isolate the fault (5). Method according to one of the preceding claims,
characterized,
that for each of the protective devices (SE ₁ , SE ₂ ) the process variables of the energy supply network (3) are detected via a converter connected to the energy supply network (3), and
in that it is determined as a function of the process variables whether an error (5) is present in the energy supply network (3). Method according to one of the preceding claims,
characterized,
in that one of the protective devices (SE ₁ , SE ₂ ) is connected via a communication channel (2) to another of the protective devices (SE ₁ , SE ₂ ), that the protective device (SE ₁ , SE ₂ ) transmits information from the communication channel (2) the other protective device (SE ₁ , SE ₂ ) detected, and
in that it is decided, depending on the information, whether the error (5) is isolated from the protective devices (SE ₁ , SE ₂ ) when an error (5) occurs in the energy supply network (3). Method according to one of the preceding claims,
characterized,
that the process automatically by a central control device (1) is executed. Method according to one of the preceding claims,
characterized,
that output steps are specified,
that each of the output steps comprises at least one input, and
in that the output steps are output as the test sequence to the protection devices (SE ₁ , SE ₂ ) in an order dependent on trigger events, each trigger event being dependent on at least one event from an event group, the event group comprising: ● expiry of a predefined period of time, ● arrival of a specific date from one of the protective devices via one communication channel to another of the protective devices, and ● A switch position of a circuit breaker is changed. Test system for testing a plurality of protective devices (SE ₁ , SE ₂ ) of a power supply network (3) arranged in spatially distributed locations,
wherein the test system comprises a control device (1) and a plurality of test devices (PE ₁ , PE ₂ ),
wherein at least one of the test devices (PE ₁ , PE ₂ ) is present at each location (USW1, USW2) of the protective devices (SE ₁ , SE ₂ ),
wherein the control device (1) has a communication connection (4, 6) to each of the test devices (PE ₁ , PE ₂ ),
wherein each of the test devices (PE ₁ , PE ₂ ) is designed to test at least one of the protective devices (SE ₁ , SE ₂ ) which is present at the same location (USW1, USW2) as the respective test device (PE ₁ , PE ₂ ), and wherein the test system (1, PE ₁ , PE ₂ ) is designed to perform the method according to any one of the preceding claims. Test system according to claim 10,
characterized,
that the control device (1) in one of the testing equipment (PE _1, PE ₂₎ is integrated. Control device (1) for a test system for testing a plurality of spatially distributed protective devices (SE ₁ , SE ₂ ) of a power supply network (3),
wherein the control device (1) is designed to communicate with a plurality of test devices (PE ₁ , PE ₂ ) assigned to the protective devices (SE ₁ , SE ₂ ),
each test device (PE ₁ ; PE ₂ ) being designed to test at least one of the protective devices (SE ₁ , SE ₂ ),
wherein the control device (1) is designed to carry out the method according to any one of claims 1-9. A computer program product having computer readable instructions stored thereon and configured to perform, when executed by a computer, the method of any one of claims 1-9.

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